select * from test where c1 in (select 1)

+---------+---------+---------+
| test.id | test.c1 | test.c2 |
+=============================+
| 0       | 1       | 1       |
|---------+---------+---------|
| 2       | 1       | 1       |
+---------+---------+---------+

explain select * from test where c1 in (select 1)

+-------------------------------------------------------------------+
| PLAN                                                              |
+===================================================================+
| Projection [test.id, test.c1, test.c2] [Project]                  |
|   LeftSemi Join On test.c1 = (1) as (_temp_table_1_.1) [HashJoin] |
|     Scan test -> [id, c1, c2] [SeqScan]                           |
|     Projection [1] [Project]                                      |
|       Dummy [Dummy]                                               |
+-------------------------------------------------------------------+