MYSQL - 按时间使用组查找计数

Question

我想找到产品的颜色，包括特定颜色的产品数量，我正在使用下面提到的查询。查询已成功执行，但需要大约2秒的时间。我们还有10个具有相同查询的过滤器。我想通知你，我已经创建了索引所有必要的字段

SELECT Count(c.url_key) AS pcount, 
   c.color_name, 
   c.url_key        AS purl_key, 
   c.color_id 
FROM   products AS p 
   INNER JOIN colors AS c 
           ON p.color_id = c.color_id 
   INNER JOIN product_filters AS f 
           ON p.color_id = f.filter_id 
   INNER JOIN product_price AS pp 
           ON p.product_id = pp.product_id 
WHERE  p.approved = 1 
GROUP  BY c.url_key 
ORDER  BY pcount DESC 

解释下面列出的颜色：

Field       Type         Null   Key Default Extra
----------- ------------ ------ --- ------- --------------
color_id    int(11)      NO     PRI NULL    auto_increment
color_name  varchar(255) NO     MUL NULL
color_code  varchar(7)   NO     MUL NULL
url_key     varchar(255) NO     UNI NULL
status      tinyint(1)   NO     MUL 1

请建议