http://hosting.gig4free.com/freewebhosting.php
I had a free website hosting account there, and PHP worked okay, but I didn't test mysql and .htacess. My account is deleted now though

The following free hosting directory page lists (currently) 78 free hosts that support mysql databases (and PHP)

http://www.free-webhosts.com/free-mysql-database.php
If the description given in the review page also lists "Custom error pages" or "Password-protected files" or "Cpanel", then it probably supports .htacess files also. The problem is most free web hosting sites do not list their features very well, so seldom list ".htacess" even if it is supported.