Force login through mysql
Sounds like you need to do the following:


Set the securepages_enable to 0 in settings.php 
Open a MySQL Client, like HeidiSQL or SQL Pro 
Truncate the cache_ tables
Reload local site in browser


This should rebuild the variables and then your runtime value will be respected.

Also, check the .htaccess file to see that you are not being redirected to HTTPS.