Disallow access / require an IP to a certain location if a query string is set

 <LocationMatch ^/test.php>
        <If "%{QUERY_STRING} =~ /action=login/">
            Require ip 192.168.178.100
        </If>
    </LocationMatch>

http://localhost/test.php works for everyone.

http://localhost/test.php?action=login works only for the ip 192.168.178.100

The “new” Apache 2.4 is different if you compare it to the 2.2 version of things. But once you understand it, it makes things easier and more readable. With 2.2 you would have needed more lines and mod_rewrite to get that working. See also Apache 2.4.x Better than rewriting