Kwik E Mart is actually in Henderson, not Las Vegas, but it is fairly close if you have a car. It is on the corner of Horizon Ridge Parkway and Stephanie Street, in Henderson, Nevada.
It is a 7-11, which has temporarily been converted into a Kwik-E-Mart from The Simpsons cartoon. As of Saturday 7 July, it is still a Kwik-E-Mart. I don't know when it will convert back to a 7-11.
I wasn't going to touch upon this again, but popular demand has made me decide to do this probably final post on the Kwik-E-Mart.
Directions to Kwik-E-Mart:
From Interstate 15 at Tropicana
Interstate 15 South to I-215 East to Henderson, exit on Stephanie Street, and go south (south is a right), and Kwik-E-Mart will be on your right in a few blocks. (2 or 3)
Roughly speaking, it is a few miles south on Stephanie Street, of Sunset Station.