EXPLAIN ANALYZE:

-> Limit: 10 row(s)  (cost=497474 rows=10) (actual time=0.179..0.3 rows=10 loops=1)
    -> Nested loop left join  (cost=497474 rows=10) (actual time=0.178..0.296 rows=10 loops=1)
        -> Nested loop left join  (cost=248737 rows=10) (actual time=0.144..0.239 rows=10 loops=1)
            -> Index scan on test_client using PRIMARY  (cost=0.0131 rows=10) (actual time=0.0782..0.148 rows=10 loops=1)
            -> Index lookup on test_join1 using client_id (client_id=test_client.id)  (cost=0.25 rows=1) (actual time=0.00824..0.00824 rows=0 loops=10)
        -> Index lookup on test_join2 using client_id (client_id=test_client.id)  (cost=0.25 rows=1) (actual time=0.0048..0.0048 rows=0 loops=10)


EXPLAIN:

+--+-----------+-----------+----------+-----+-------------+---------+-------+----------------------------+----+--------+-----+
|id|select_type|table      |partitions|type |possible_keys|key      |key_len|ref                         |rows|filtered|Extra|
+--+-----------+-----------+----------+-----+-------------+---------+-------+----------------------------+----+--------+-----+
|1 |SIMPLE     |test_client|null      |index|null         |PRIMARY  |4      |null                        |10  |100     |null |
|1 |SIMPLE     |test_join1 |null      |ref  |client_id    |client_id|5      |hashjoinissue.test_client.id|1   |100     |null |
|1 |SIMPLE     |test_join2 |null      |ref  |client_id    |client_id|5      |hashjoinissue.test_client.id|1   |100     |null |
+--+-----------+-----------+----------+-----+-------------+---------+-------+----------------------------+----+--------+-----+