在大型表MySQL上优化ORDER BY查询

I have a browse category query that im trying to optimize. Im ending up with Using temporary; Using filesort in the explain and the query is slow on a category with say 60,000 rows. If i remove the Order By clauses the query runs very fast .05 seconds to do 60,000 rows. With the Order By clauses its very slow around 5 seconds. Parts contains some 500,000 rows as does Parts_Category.I have a browse category query that im trying t