Add missing index on "oc_oauth2_access_tokens"("token")

[butonic]

mysql> SHOW INDEXES FROM oc_oauth2_access_tokens;
+-------------------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
| Table                   | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | Visible | Expression |
+-------------------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
| oc_oauth2_access_tokens |          0 | PRIMARY  |            1 | id          | A         |           0 |     NULL |   NULL |      | BTREE      |         |               | YES     | NULL       |
+-------------------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
1 row in set (0.00 sec)

so the SELECT where token query has to do a full table scan:

mysql> EXPLAIN SELECT * FROM oc_oauth2_access_tokens WHERE token = 'a very long token ...';
+----+-------------+-------------------------+------------+------+---------------+------+---------+------+------+----------+-------------+
| id | select_type | table                   | partitions | type | possible_keys | key  | key_len | ref  | rows | filtered | Extra       |
+----+-------------+-------------------------+------------+------+---------------+------+---------+------+------+----------+-------------+
|  1 | SIMPLE      | oc_oauth2_access_tokens | NULL       | ALL  | NULL          | NULL | NULL    | NULL |    1 |   100.00 | Using where |
+----+-------------+-------------------------+------------+------+---------------+------+---------+------+------+----------+-------------+
1 row in set, 1 warning (0.00 sec)

how to fix?

mysql> CREATE UNIQUE INDEX oauth2_token ON oc_oauth2_access_tokens(token);
Query OK, 0 rows affected (0.08 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> EXPLAIN SELECT * FROM oc_oauth2_access_tokens WHERE token = 'a very long token ...';
+----+-------------+-------------------------+------------+------+---------------+--------------+---------+-------+------+----------+-------+
| id | select_type | table                   | partitions | type | possible_keys | key          | key_len | ref   | rows | filtered | Extra |
+----+-------------+-------------------------+------------+------+---------------+--------------+---------+-------+------+----------+-------+
|  1 | SIMPLE      | oc_oauth2_access_tokens | NULL       | ref  | oauth2_token  | oauth2_token | 194     | const |    1 |   100.00 | NULL  |
+----+-------------+-------------------------+------------+------+---------------+--------------+---------+-------+------+----------+-------+
1 row in set, 1 warning (0.00 sec)

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