Try fastening your seatbelt!
Had the same trouble with a Toyota Tarago, door was locked and unable to unlock. So had to cut hole on external of door to unlock.
because a seat belt might be jammed
a crowbar will do it or a stillsaw
That would depend on why it is stuck. If the problem is with the latch mechanism assembly, you have to remove the door panel from inside the car ( loads of fun with the door shut) and pop the latch open from inside. If the door is simply stuck shut because it's jammed on something, from the inside of the car, hold the door handle in the release position and kick it open without damaging anything.
remove door card,remove door rubber and interior arch trim panel,unclip lower seat base,this should give you access to the latch mechanism on the door shut,now have someone outside of car hold door handle in open position whilst they apply pressure to door (as if pushing shut) now simply lever locking latch up with a screwdriver or similar until it is clear of the door shut lock post and in open position
"Shut your mouth and open the door." (Shut up and open the door!)
door open from inside or outside
You shut the front door
Often the latch has been closed and the door won't catch until the latch is popped back. Use a screwdriver or other tool, make sure the door is unlocked then operate the inside door handle and open the latch lever with the screwdriver.