National Sports Center Basketball Facility
The brand new NSC Basketball Facility has open gym times available. You can check out their schedule here. Look for the "Court Schedule" section on that web page.
The Lab Athletic
The Lab Athletic, a new basketball facility in Ham Lake (formerly the old Jam Hops building), has open gym occasionally. Follow their Facebook page to get updates when open gym times are available:
Mounds View Community Center
Mounds View Community Center has open gym available. Call their number (763) 717-4040, or visit their website for availability.