acquire two locks in one statement, lock is not acquired in parallel

## Bug Report

Please answer these questions before submitting your issue. Thanks!

### 1. Minimal reproduce step (Required)
```sql
1. select get_lock('test1',200); in session A
2. SELECT GET_LOCK('test1',200), GET_LOCK('test2',200); in session B
3. select get_lock('test2',200); in session A
```

### 2. What did you expect to see? (Required)
step 2 expect :
```sql
+-----------------------+-----------------------+
| GET_LOCK('test1',200) | GET_LOCK('test2',200) |
+-----------------------+-----------------------+
| 0 | 1 |
+-----------------------+-----------------------+
```
step 3 expect : return 0

### 3. What did you see instead (Required)
step 3 return 1 in session A
step 2 : both locks are returned 0, and acquired time is 400 second
```sql
+-----------------------+-----------------------+
| GET_LOCK('test1',200) | GET_LOCK('test2',200) |
+-----------------------+-----------------------+
| 0 | 0 |
+-----------------------+-----------------------+
1 row in set (6 min 40.01 sec)
```

### 4. What is your TiDB version? (Required)

| Release Version: v6.1.0-alpha
Edition: Community
Git Commit Hash: 90e24b92eda05d04dc6c69fa97ffd89f617717ee
Git Branch: heads/refs/tags/v6.1.0-alpha
UTC Build Time: 2022-05-15 14:57:27
GoVersion: go1.18
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false |