This may sound a bit of "out there", but a large part of my business is commercial door locks and locks do not like dirt and 'gunk'.
This is my first experience with the laser cut keys, and in the 3 months I've had my Colorado, I've notice "gunk" piling up in the groove of the key towards the bow, and also notice some resistant in turning the key back out lately. A couple days ago I took a knife and cleaned out all the gunk that had collected in the cut of the key. The problem went away.
I won't say that is the problem here, but I do know lock cylinders are particular to key alignment in them, and the smallest fraction of misalignment can bind the key in the cylinder, and the crap collected in the key 's cut will push against alignment and cause a bind.
Also, Never use WD40 in a lock, as you are promoting dirt collection, as it will stick to the residue.
'16 Colorado 4x4 Z71 , Duramax, CC, SB, Bose/Nav