MySQL query slow even with indexes

Structure of my table mysql> show create table t_group_tag_relation\G *************************** 1. row *************************** Table: t_group_tag_relation Create Table: CREATE TABLE t_group_tag_relation ( id int(11) NOT NULL AUTO_INCREMENT, domain_id int(11) NOT NULL, group_tag_id int(11) NOT NULL, resource_id int(11) NOT NULL, resource_type int(11) DEFAULT NULL, PRIMARY KEY (id), UNIQUE KEY group_tag_id_resource_id (group_tag_id,resource_id), KEY domain_id (domain_id,group_tag_id,resource_type,resource_id), KEY domain_id_resource_type (domain_id,resource_type) ) ENGINE=InnoDB AUTO_INCREMENT=1613462 DEFAULT CHARSET=latin1 1 row in set (0.03 sec) Explain plan of my query mysql> explain select * from t_group_tag_relation WHERE resource_id = 575868070 AND domain_id = 476 AND resource_type = 2; +----+-------------+----------------------+------+-----------------------------------+-----------+---------+-------+-------+--------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+----------------------+------+-----------------------------------+-----------+---------+-------+-------+--------------------------+ | 1 | SIMPLE | t_group_tag_relation | ref | domain_id,domain_id_resource_type | domain_id | 4 | const | 28400 | Using where; Using index | +----+-------------+----------------------+------+-----------------------------------+-----------+---------+-------+-------+--------------------------+ 1 row in set (0.57 sec) It is using indexes already but performance is not good. How to improve performance?