my BUSH TV is locked. plz help to unlock it?

I have an old model Bush tv, model name is Unique141. My 5 year old niece locked it suddenly.don't know what to do. The tv screen turned blue and only "LOCK" is appearing on the left of the screen.no buttons of the tv nor remote is working.we didn't set any lock code.can't understand what to do.the remote model of my tv is
BUSH 141/201/211..plz help me