''LOCKED'' button is stuck on oven, but door is not closed

Check the door switch. you probably tripped it while cleaning..

If you've interrupted the clean cycle or have accidentally set the clean cycle "with the oven door open,"or u forgot to close the door and started cleaning then  the latch may have engaged and now the door can't be closed because it will hit the latch. There may be a door activated* switch on the front face of the machine. In this case you may need to manually press that door switch with your finger while at the same time canceling the clean cycle to get the latch to retract so the door can close fully again.
On -some- Frigidaire built ranges, the switch is located behind the right hand side panel and activated by the right hand door hinge. On this model, the side panel may need to be removed to access a malfunctioning door switch.

If the lock does not open after the machine has cooled down, you can try....1) Unplugging the range or shut off the circuit breaker for 5 minutes. Plug the range back in or turn on the circuit breaker. Set the clock and try moving the door lock lever or opening the door. 2) Set the self-clean cycle again and only allow it to work for 15 minutes. Cancel the self-clean cycle and allow the oven to cool. Gently try moving the door lock lever or opening the door.

Check your door is not jma with anything.
try to power off for 1 hours then try.
also check there is a key for unlock .

Wait for the cycle to end and it will unlock the latch Here to help Shaun

Hold the lock button for 3-5 seconds...

Simple ,,,,,,,,,,,,,and i hope it wld solve ur issue :)