i wish some folks would just hearken to how guns were cared for back in the day. they'd see that all the concoctions and chemicals that are touted by legions are just not necessary and, in the long run, will do more harm than good.
as to the lock, it will usually pay dividends to take it completely apart and level the the lock plate (with a file), then put it all back together and sparsely oil all moving pivot point parts, then screw it back to the gun's lock mortise.
it would do us all good to attend to our firearms as soon as possible and not procrastinate. this is the absolute best thing one can do with regards to gun maintenance. in doing so, dihydrogen monoxide (plain tepid tap water) will be your best friend, and your gun's, too. again, there is no need to affront your gun with harsh chemicals! use water and water soluble oil. this will make everyone - gun and shooter - very happy campers in the long run. promise.