Explain Query (mysql)
EXPLAIN SELECT * FROM `subscriptions` `t` WHERE `t`.`user_id`='308842' LIMIT 1
| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | filtered | Extra |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | SIMPLE | t | const | uniq_sub_per_user, idx_user_id | uniq_sub_per_user | 4 | const | 1 | 100.00 |