First I edited this eye to make it look less squinted. This way in the gif I could make it look like he is looking in and the eye will open/close a little as he looks. I moved the eyebrow too, but it ended up not being visible through the keyhole.

I put the face between a black background and the keyhole with the actual hole cut out so it was like a window. I used the grid to see how much I was moving the eye. I moved it first in one direction, with the changing eye size in the middle, then moved it back again. Making the gif along the way.

I actually ended up with 62 layers, but my program has a limit to both the number of frames a gif can have so I had to cut it by half and shrink it to make it save. I think I was left with 32 layers by the time it would agree to save this file.