_system_date_format_types_build() causes a filesort

mysql> EXPLAIN SELECT dft.type, dft.title, dft.locked FROM date_format_type dft ORDER BY dft.title;
+----+-------------+-------+------+---------------+------+---------+------+------+----------------+
| id | select_type | table | type | possible_keys | key  | key_len | ref  | rows | Extra          |
+----+-------------+-------+------+---------------+------+---------+------+------+----------------+
|  1 | SIMPLE      | dft   | ALL  | NULL          | NULL | NULL    | NULL |    3 | Using filesort | 
+----+-------------+-------+------+---------------+------+---------+------+------+----------------+
1 row in set (0.03 sec)