Bumped into a joist while drilling for a toggle bolt
Running your 1/2" bit into the joist a ways may give you the clearance you need to get the toggler to expand. 

Otherwise, I'd drill a hole in the joist slightly smaller than the toggle bolt, run that bolt (without the toggle wings) into the hook, and thread the bolt directly into the wood. It'll hold as well as the drywall would have if you keep it snug. 

If that's not suitable, your local hardware store may have a longer version of the other (dual-thread) bolt.