+-------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table       | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+-------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| wp_postmeta |          0 | PRIMARY  |            1 | meta_id     | A         |     1350193 |     NULL | NULL   |      | BTREE      |         |               |
| wp_postmeta |          1 | post_id  |            1 | post_id     | A         |      450064 |     NULL | NULL   |      | BTREE      |         |               |
| wp_postmeta |          1 | meta_key |            1 | meta_key    | A         |          19 |     NULL | NULL   | YES  | BTREE      |         |               |
+-------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+