I don't know how quick the latch has to be, but...

The way my bumper swing-out tire carrier latches (made by Garwin) is... There is a vertical tab welded to the top rear edge of the left side of the bumper (pivot is on the right side), and there is a hole drilled in this tab, with a nut welded to the back of it.

On the swinging part, there is a corresponding tab with a hole drilled through it. When the swinging part is shut, the two tabs line up. A coarse-threaded bolt is put through the hole in the swinging part tab and it screws into the tab on the bumper. Instead of a hex head on the bolt, they have welded an oval loop to the bolt, and the loop is big enoudh to put the four fingers of your hand into. Makes it easy to screw in the bolt. The end of the bolt has a small hold drilled crossways through it, so that after the bolt is screwed in, you can snap a hitch pin through the hole to keep the bolt from backing out.

I know it sounds a lot more complicated that it is, but it's really easy and sturdy. It takes 5 to 10 seconds to latch it, which is a lot longer than a snap latch, but it's a lot sturdier.