Depends on the driver in that keychain laser. You could also replace the driver circuit. But even if you could turn the driver up to the required current rating, those button cells would last maybe three seconds.
It'd be a lot cheaper to just buy a higher powered unit from o-like or even Laserlands; or better yet at least learning how to do the build yourself to allow you flexibility in the future.
So yes, it's *possible* but you'd probably not be too happy with the result.