+----+--------------------+----------------+--------+---------------------------------+------------+---------+----------------------+--------+----------+-----------------------------------------------------------+
| id | select_type        | table          | type   | possible_keys                   | key        | key_len | ref                  |   rows | filtered | Extra                                                     |
+----+--------------------+----------------+--------+---------------------------------+------------+---------+----------------------+--------+----------+-----------------------------------------------------------+
|  1 | PRIMARY            | e              | range  | id_usuario,registros,registros3 | registros3 |       4 | NULL                 | 108250 |    99.93 | Using where; Using index; Using temporary; Using filesort |
|  1 | PRIMARY            | a              | eq_ref | PRIMARY,correos6                | PRIMARY    |       4 | saltos.e.id_registro |      1 |   100.00 | Using where                                               |
|  6 | MATERIALIZED       | tbl_usuarios_c | range  | PRIMARY,id_usuario              | id_usuario |       4 | NULL                 |      2 |   100.00 | Using index condition; Using where                        |
|  5 | MATERIALIZED       | tbl_indexing   | ref    | indexing2,indexing3             | indexing2  |       4 | const                | 252182 |   100.00 |                                                           |
|  3 | DEPENDENT SUBQUERY | tbl_correo_a   | ref    | correos                         | correos    |       4 | saltos.a.id          |      4 |   100.00 | Using where; Using index                                  |
|  2 | DEPENDENT SUBQUERY | tbl_usuarios_c | eq_ref | PRIMARY                         | PRIMARY    |       4 | saltos.a.id_cuenta   |      1 |   100.00 |                                                           |
+----+--------------------+----------------+--------+---------------------------------+------------+---------+----------------------+--------+----------+-----------------------------------------------------------+