The graham cracker crust of any no bake cheesecake tends to become a little soggy when refrigerated for more than a few hours. If you want to keep a crispier base, you can add a very light egg wash over top of the base and bake it briefly (350 for 5 minutes). The egg wash will form a barrier between the base and the filling preventing any sogginess. If you do choose to take this step, make absolutely sure the base is completely cool before adding the cream cheese mixture.