Have you tried pushing down on the seat slightly while trying to turn the key?
Otherwise maybe a wire with a hook on the tip to try and hook the cable somewhere and pull it? Don't have a 660 anymore so can't confirm if it will work unfortunately, I'm thinking from memory.
A final update on the issue (few weeks after I got the bike back). We went into lockdown, Honda Tygerberg moved, my bike was moved to Honda Cape Town. etc.
The problem was finally diagnosed as a faulty spark plug lead where it goes into the bit that goes on top of the spark plug. Honda replaced...
Lrfan where do you fill up or where did you fill up? My AT starting doing the same on Thursday. I filled up at Engen next to Velodrome on Wednesday.. Been filling there for months.