I have a frame mounted AXA Defender cafe wheel lock with plug in chain. Defender*-*axa-stenman
If I'm just running in someplace quick or will be within sight of the bike I can just snap the cafe lock closed. If I will be a while or out of sight I simply loop the chain around something, and plug it into the cafe lock, then its double locked, cut the chain and it still can't be ridden away..
One of the advantages of a high quality cafe lock is that they are difficult to access with many of the most expedient methods used to defeat a lock as its mounted behind the seat stays.