Kryptonite 712 Keeper cable lock is what you want. I’ve had one of those retractable Abus cables and the locking mechanism and retractor broke. I’ve also snapped a 712 with my hands when a hinge jammed, but I still think it is a reasonable solution for a “snatch and ride” theft. I used it to lock four bikes together on Brighton Beach for our Fish and Chips while we sat next to them. That is the level of security it’s good for.
The other Kryptonite listed above with two cables is far too bulky for the OP. I keep one in the boot for locking bikes inside the car to a luggage loop and on the roof rack. It is a good deterent, but you would not want to carry it on a road bike.