Put it on the cut between two scenes, then follow it with the Law and Order Dun Dun sting when you want a second, more serious shift in the same edit. Keep it as the bridge, not the ending, and let the next clip start straight after it.
About this sound
This is a short, punchy bass riff, about a second and a half long, with a funky slap-bass line at its centre. It feels playful and knowing, like a wink to the audience before the next joke lands. It comes from Seinfeld, where a bass riff like this marked the move from one scene to the next.