+----+--------------+---------------+-------+---------------+---------+---------+-------+------+-------+
| id | select_type  | table         | type  | possible_keys | key     | key_len | ref   | rows | Extra |
+----+--------------+---------------+-------+---------------+---------+---------+-------+------+-------+
|  1 | PRIMARY      | keywordmaster | const | PRIMARY       | PRIMARY | 8       | const |    1 |       |
|  2 | UNION        | keywordmaster | const | PRIMARY       | PRIMARY | 8       | const |    1 |       |
| NULL | UNION RESULT | <union1,2>    | ALL   | NULL          | NULL    | NULL    | NULL  | NULL |       |
+----+--------------+---------------+-------+---------------+---------+---------+-------+------+-------+