diff --git a/src/main/java/roomescape/payment/infrastructure/persistence/CanceledPaymentRepository.kt b/src/main/java/roomescape/payment/infrastructure/persistence/CanceledPaymentRepository.kt
index cb5d2e53..70466653 100644
--- a/src/main/java/roomescape/payment/infrastructure/persistence/CanceledPaymentRepository.kt
+++ b/src/main/java/roomescape/payment/infrastructure/persistence/CanceledPaymentRepository.kt
@@ -1,8 +1,7 @@
 package roomescape.payment.infrastructure.persistence
 
 import org.springframework.data.jpa.repository.JpaRepository
-import java.util.*
 
 interface CanceledPaymentRepository : JpaRepository<CanceledPaymentEntity, Long> {
-    fun findByPaymentKey(paymentKey: String): Optional<CanceledPaymentEntity>
+    fun findByPaymentKey(paymentKey: String): CanceledPaymentEntity?
 }
diff --git a/src/main/java/roomescape/payment/infrastructure/persistence/PaymentRepository.kt b/src/main/java/roomescape/payment/infrastructure/persistence/PaymentRepository.kt
index c0ccd469..bf83f375 100644
--- a/src/main/java/roomescape/payment/infrastructure/persistence/PaymentRepository.kt
+++ b/src/main/java/roomescape/payment/infrastructure/persistence/PaymentRepository.kt
@@ -1,10 +1,14 @@
 package roomescape.payment.infrastructure.persistence
 
 import org.springframework.data.jpa.repository.JpaRepository
-import java.util.*
+import org.springframework.data.jpa.repository.Query
 
 interface PaymentRepository : JpaRepository<PaymentEntity, Long> {
-    fun findByReservationId(reservationId: Long): Optional<PaymentEntity>
 
-    fun findByPaymentKey(paymentKey: String): Optional<PaymentEntity>
+    fun existsByReservationId(reservationId: Long): Boolean
+
+    @Query("SELECT p.paymentKey FROM PaymentEntity p WHERE p.reservation.id = :reservationId")
+    fun findPaymentKeyByReservationId(reservationId: Long): String?
+
+    fun findByPaymentKey(paymentKey: String): PaymentEntity?
 }
diff --git a/src/test/java/roomescape/payment/business/PaymentServiceTest.java b/src/test/java/roomescape/payment/business/PaymentServiceTest.java
index ee975e38..10a5dbb8 100644
--- a/src/test/java/roomescape/payment/business/PaymentServiceTest.java
+++ b/src/test/java/roomescape/payment/business/PaymentServiceTest.java
@@ -17,6 +17,7 @@ import roomescape.common.exception.RoomescapeException;
 import roomescape.member.infrastructure.persistence.Member;
 import roomescape.member.infrastructure.persistence.MemberRepository;
 import roomescape.member.infrastructure.persistence.Role;
+import roomescape.payment.infrastructure.persistence.CanceledPaymentEntity;
 import roomescape.payment.infrastructure.persistence.CanceledPaymentRepository;
 import roomescape.payment.web.PaymentApprove;
 import roomescape.payment.web.PaymentCancel;
@@ -88,7 +89,7 @@ class PaymentServiceTest {
 		PaymentCancel.Request paymentCancelRequest = paymentService.cancelPaymentByAdmin(reservation.getId());
 
 		// then
-		assertThat(canceledPaymentRepository.findByPaymentKey("payment-key")).isNotEmpty();
+		assertThat(canceledPaymentRepository.findByPaymentKey("payment-key")).isNotNull();
 		assertThat(paymentCancelRequest.paymentKey).isEqualTo(paymentInfo.paymentKey);
 		assertThat(paymentCancelRequest.cancelReason).isEqualTo("고객 요청");
 		assertThat(paymentCancelRequest.amount).isEqualTo(10000L);
@@ -127,8 +128,10 @@ class PaymentServiceTest {
 		paymentService.updateCanceledTime(paymentInfo.paymentKey, canceledAt);
 
 		// then
-		canceledPaymentRepository.findByPaymentKey(paymentInfo.paymentKey)
-			.ifPresent(canceledPayment -> assertThat(canceledPayment.getCanceledAt()).isEqualTo(canceledAt));
+		CanceledPaymentEntity canceledPayment = canceledPaymentRepository.findByPaymentKey(paymentInfo.paymentKey);
+
+		assertThat(canceledPayment).isNotNull();
+		assertThat(canceledPayment.getCanceledAt()).isEqualTo(canceledAt);
 	}
 
 	@Test
diff --git a/src/test/java/roomescape/reservation/controller/ReservationControllerTest.java b/src/test/java/roomescape/reservation/controller/ReservationControllerTest.java
index 62577810..a026ee41 100644
--- a/src/test/java/roomescape/reservation/controller/ReservationControllerTest.java
+++ b/src/test/java/roomescape/reservation/controller/ReservationControllerTest.java
@@ -447,13 +447,12 @@ public class ReservationControllerTest {
 			.statusCode(400);
 
 		// then
-		Optional<CanceledPaymentEntity> canceledPaymentOptional = canceledPaymentRepository.findByPaymentKey(
-			paymentKey);
-		assertThat(canceledPaymentOptional).isNotNull();
-		assertThat(canceledPaymentOptional.get().getCanceledAt()).isEqualTo(canceledAt);
-		assertThat(canceledPaymentOptional.get().getCancelReason()).isEqualTo("고객 요청");
-		assertThat(canceledPaymentOptional.get().getCancelAmount()).isEqualTo(1000L);
-		assertThat(canceledPaymentOptional.get().getApprovedAt()).isEqualTo(approvedAt);
+		CanceledPaymentEntity canceledPayment = canceledPaymentRepository.findByPaymentKey(paymentKey);
+		assertThat(canceledPayment).isNotNull();
+		assertThat(canceledPayment.getCanceledAt()).isEqualTo(canceledAt);
+		assertThat(canceledPayment.getCancelReason()).isEqualTo("고객 요청");
+		assertThat(canceledPayment.getCancelAmount()).isEqualTo(1000L);
+		assertThat(canceledPayment.getApprovedAt()).isEqualTo(approvedAt);
 	}
 
 	@DisplayName("테마만을 이용하여 예약을 조회한다.")
diff --git a/src/test/java/roomescape/reservation/service/ReservationWithPaymentServiceTest.java b/src/test/java/roomescape/reservation/service/ReservationWithPaymentServiceTest.java
index 4f74c7e6..b0f589c3 100644
--- a/src/test/java/roomescape/reservation/service/ReservationWithPaymentServiceTest.java
+++ b/src/test/java/roomescape/reservation/service/ReservationWithPaymentServiceTest.java
@@ -17,6 +17,7 @@ import roomescape.member.infrastructure.persistence.Member;
 import roomescape.member.infrastructure.persistence.MemberRepository;
 import roomescape.member.infrastructure.persistence.Role;
 import roomescape.payment.infrastructure.persistence.CanceledPaymentRepository;
+import roomescape.payment.infrastructure.persistence.PaymentEntity;
 import roomescape.payment.infrastructure.persistence.PaymentRepository;
 import roomescape.payment.web.PaymentApprove;
 import roomescape.payment.web.PaymentCancel;
@@ -76,13 +77,13 @@ class ReservationWithPaymentServiceTest {
 				assertThat(reservation.getReservationTime().getId()).isEqualTo(time.getId());
 				assertThat(reservation.getReservationStatus()).isEqualTo(ReservationStatus.CONFIRMED);
 			});
-		paymentRepository.findByPaymentKey("payment-key")
-			.ifPresent(payment -> {
-				assertThat(payment.getReservation().getId()).isEqualTo(reservationResponse.id());
-				assertThat(payment.getPaymentKey()).isEqualTo("payment-key");
-				assertThat(payment.getOrderId()).isEqualTo("order-id");
-				assertThat(payment.getTotalAmount()).isEqualTo(10000L);
-			});
+
+		PaymentEntity payment = paymentRepository.findByPaymentKey("payment-key");
+		assertThat(payment).isNotNull();
+		assertThat(payment.getReservation().getId()).isEqualTo(reservationResponse.id());
+		assertThat(payment.getPaymentKey()).isEqualTo("payment-key");
+		assertThat(payment.getOrderId()).isEqualTo("order-id");
+		assertThat(payment.getTotalAmount()).isEqualTo(10000L);
 	}
 
 	@Test
@@ -109,8 +110,8 @@ class ReservationWithPaymentServiceTest {
 		// then
 		assertThat(paymentCancelRequest.cancelReason).isEqualTo("고객 요청");
 		assertThat(reservationRepository.findById(reservationResponse.id())).isEmpty();
-		assertThat(paymentRepository.findByPaymentKey("payment-key")).isEmpty();
-		assertThat(canceledPaymentRepository.findByPaymentKey("payment-key")).isNotEmpty();
+		assertThat(paymentRepository.findByPaymentKey("payment-key")).isNull();
+		assertThat(canceledPaymentRepository.findByPaymentKey("payment-key")).isNotNull();
 	}
 
 	@Test