That key binding was the same issue I had about a year ago, turned out it was a recall, so I would first call a local dealership and give them your last 8 of the VIN to see if its still open. GM HQ will cover the cost of parts/labor, maybe even the tow to there. Wouldn't hurt to call for free.
2009 Cobalt LS XFE U74
Mods: K&N Typhoon Intake, Option Cat-Back Exhaust, Cosmo Short shifter, Maxxim Ahead 17X7's, MPx shorty antenna, FE5 Strut/shocks, Tein S Techs, Moog endlinks, Moog spring seaters, ZZP shorty header, LSJ downpipe, LNF front grille