From Brownstoner Queens:
A one-story mosque at 24-30 Steinway Street in Astoria has been demolished (or not quite demolished, it seems, as there are only alteration permits as opposed to new building permits on file) to make way for a five-story structure that will house a school in addition to religious facilities, according to DOB permits. Based on this DOB violation, it seems safe to surmise that the Al Iman Center (aka the Al Marwa Center) has been operating in one form or another since the mid-1990s.
Okay, Skippy, the mosque hasn't been demolished. Isabella's has been demolished. You can see the rendering of the school in the window of this Google Maps shot: