diff --git a/chsm-common/src/main/java/com/sunyard/chsm/mapper/KeyRecordMapper.java b/chsm-common/src/main/java/com/sunyard/chsm/mapper/KeyRecordMapper.java
new file mode 100644
index 0000000..7604932
--- /dev/null
+++ b/chsm-common/src/main/java/com/sunyard/chsm/mapper/KeyRecordMapper.java
@@ -0,0 +1,14 @@
+package com.sunyard.chsm.mapper;
+
+import com.baomidou.mybatisplus.core.mapper.BaseMapper;
+import com.sunyard.chsm.model.entity.KeyInfo;
+import com.sunyard.chsm.model.entity.KeyRecord;
+import org.apache.ibatis.annotations.Mapper;
+
+/**
+ * @author liulu
+ * @since 2024/10/22
+ */
+@Mapper
+public interface KeyRecordMapper extends BaseMapper<KeyRecord> {
+}
diff --git a/chsm-common/src/main/java/com/sunyard/chsm/service/KeyRecordService.java b/chsm-common/src/main/java/com/sunyard/chsm/service/KeyRecordService.java
new file mode 100644
index 0000000..bc1f146
--- /dev/null
+++ b/chsm-common/src/main/java/com/sunyard/chsm/service/KeyRecordService.java
@@ -0,0 +1,15 @@
+package com.sunyard.chsm.service;
+
+import com.sunyard.chsm.model.entity.KeyRecord;
+
+public interface KeyRecordService {
+    KeyRecord selectById(Long id);
+
+
+    /**
+     * 根据 keyId 查找密钥
+     * @param keyId keyId
+     * @return 可用值或 null
+     */
+    KeyRecord selectByKeyId(Long keyId);
+}
diff --git a/chsm-common/src/main/java/com/sunyard/chsm/service/impl/KeyRecordServiceImpl.java b/chsm-common/src/main/java/com/sunyard/chsm/service/impl/KeyRecordServiceImpl.java
new file mode 100644
index 0000000..7a32a8a
--- /dev/null
+++ b/chsm-common/src/main/java/com/sunyard/chsm/service/impl/KeyRecordServiceImpl.java
@@ -0,0 +1,45 @@
+package com.sunyard.chsm.service.impl;
+
+
+import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
+import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
+import com.sunyard.chsm.mapper.KeyRecordMapper;
+import com.sunyard.chsm.model.entity.KeyRecord;
+import com.sunyard.chsm.service.KeyRecordService;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import javax.annotation.Resource;
+import java.time.LocalDateTime;
+
+/**
+ * @author Cheney
+ */
+@Slf4j
+@Service
+@Transactional
+public class KeyRecordServiceImpl implements KeyRecordService {
+
+    @Resource
+    private KeyRecordMapper keyRecordMapper;
+
+    @Override
+    public KeyRecord selectById(Long id) {
+        return keyRecordMapper.selectById(id);
+    }
+
+    @Override
+    public KeyRecord selectByKeyId(Long keyId) {
+        LocalDateTime now = LocalDateTime.now();
+        LambdaQueryWrapper<KeyRecord> queryWrapper = new LambdaQueryWrapper<>();
+        // 添加 keyId 的条件
+        queryWrapper.eq(KeyRecord::getKeyId, keyId);
+        // 添加 effectiveTime 小于当前时间的条件
+        queryWrapper.lt(KeyRecord::getEffectiveTime, now);
+        // 添加 expiredTime 大于当前时间的条件
+        queryWrapper.gt(KeyRecord::getExpiredTime, now);
+
+        return keyRecordMapper.selectOne(queryWrapper);
+    }
+}
diff --git a/chsm-web-server/src/test/java/com/sunyard/chsm/service/SYMEncryptControllerTest.java b/chsm-web-server/src/test/java/com/sunyard/chsm/service/SYMEncryptControllerTest.java
new file mode 100644
index 0000000..ca5ca23
--- /dev/null
+++ b/chsm-web-server/src/test/java/com/sunyard/chsm/service/SYMEncryptControllerTest.java
@@ -0,0 +1,28 @@
+package com.sunyard.chsm.service;
+
+import com.sunyard.chsm.WebServerApp;
+import com.sunyard.chsm.model.dto.KeyInfoDTO;
+import com.sunyard.chsm.model.entity.KeyRecord;
+import lombok.extern.slf4j.Slf4j;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@Slf4j
+@SpringBootTest(classes = WebServerApp.class)
+public class SYMEncryptControllerTest {
+
+    private static final long TEST_APP_ID = 1852232967292882946L;
+    private static final long TEST_KEY_ID = 1852232967292882945L;
+
+    @Autowired
+    private KeyRecordService keyRecordService;
+
+
+    @Test
+    void testSelectKey() {
+        KeyRecord key = keyRecordService.selectByKeyId(TEST_KEY_ID);
+        System.out.println(key);
+    }
+
+}