Standard method for importing animated objects?

I am animating a chest to import into my game. The animation will be it opening and closing.

The simplest method that I already know is to animate it with a skeletal mesh and import it into UE4. I know that I can’t use the basic animation to import it because it UE4 requires that it has a skeletal mesh.

But using bones to animate an object which doesn’t bend or have any complex parts seems inappropriate.

So how should I do it?