Without fast path, TiDB will return wrong row with plan cache

## Bug Report

Please answer these questions before submitting your issue. Thanks!

### 1. Minimal reproduce step (Required)

```
create table t (a int, b int);
insert t values (1, 7), (1, 8), (1, 9);
prepare stmt from 'select * from t where _tidb_rowid = ?';
set @a=2;
execute stmt using @a;
set @a=1;
execute stmt using @a;
```

### 2. What did you expect to see? (Required)

```
1 8
1 7
```

### 3. What did you see instead (Required)

```
1 8
1 8
```

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