id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	roles	NULL	ALL	PRIMARY	NULL	NULL	NULL	1	100.00	NULL
1	SIMPLE	role_user_relations	NULL	ref	FK_role_user_relations_roles,FK_role_user_relations_user	FK_role_user_relations_roles	4	portal.roles.id	1	100.00	Using where; FirstMatch(roles)