MySQL-从联接表中查找与所有行匹配的行

表1:曲目

表2:单词表

表3:N:M音轨包含单词(音轨单词)

Table 3: N:M Track has Words (trackwords)

查找所有包含所有单词的曲目.

Find all tracks which have all the words.

当前查询如下:

SELECT DISTINCT t.id FROM track as t
Left Join trackwords as tw ON t.id=tw.trackid
Left Join wordlist as wl on wl.id=tw.wordid
WHERE 
wl.trackusecount>0 
group by t.id
HAVING SUM(IF(wl.word IN ('folsom','prison','blues'),1,0)) = 3;

根据EXPLAIN的说明，它使用了所有必要的索引:

Which according to EXPLAIN is using all indexes neccessary:

+----+-------------+-------+--------+-----------------------+---------+---------+----------------+---------+-------------+
| id | select_type | table | type   | possible_keys         | key     | key_len | ref            | rows    | Extra       |
+----+-------------+-------+--------+-----------------------+---------+---------+----------------+---------+-------------+
|  1 | SIMPLE      | t     | index  | PRIMARY               | PRIMARY | 4       | NULL           | 8194507 | Using index | 
|  1 | SIMPLE      | tw    | ref    | wordid,trackid        | trackid | 4       | mbdb.t.id      |       3 | Using where | 
|  1 | SIMPLE      | wl    | eq_ref | PRIMARY,trackusecount | PRIMARY | 4       | mbdb.tw.wordid |       1 | Using where | 
+----+-------------+-------+--------+-----------------------+---------+---------+----------------+---------+-------------+

但是查询需要很长时间. 有什么建议可以加快查询速度?

But the query takes ages. Any suggestion to speedup the query?