Troubleshoot Slow MySQL Queries
A normal MySQL powered website will cache its results for a while, which makes troubleshooting slow queries very unpractical as they will only be slow on initial loads. Using SQL_NO_CACHE should give you a realistic load time per query as long as the query is not already cached.
Turning off caching per query can be very helpful when troubleshooting:
SELECT SQL_NO_CACHE * FROM tblTable