I’ll bet the cloth has been snagged when lid closed. The fact the key turns indicates the lock cylinder is working as designed. The problem lies in the jaws of the latch, it is bound up with cloth and reluctant to retract.
If you can keep the key turned, and apply up and down force to the lid, you may overcome the cloth. Be careful not to twist off the head of the key, it was not designed to accept much torsional force.
The following method will destroy the lock’s outer chrome trim, but inserting a screw driver while key is in lock to assist in turning may overcome the resistance. You will need to get a new cap, or have a new lock re-pined to match existing key if there are no caps to be had locally.
Years ago I always had these chrome caps on hand just for this sort of problem._________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC
