Slow GET request for ?sccss=1&ver=3.7.1

I am assuming the request for ?sccss=1&ver=3.7.1 comes from the Simple Custom CSS. When I run a gtmetrix.com performance report, the GET request for http://www.vedostek.net/?sccss=1&ver=3.7.1 always takes the longest, on average 2-4 seconds.

I am using WP-Supercache and WP-Minify, so this may be a catching issue unrelated to the Simple Custom CSS. But I was just wondering in case it does have something to do with how this plugin is interacting with my site is the reason for slow GET response time.

http://wordpress.org/plugins/simple-custom-css/