Verses with the word locked in the Old Testament (2 verses):

Judges 3:23
Then Ehud went forth through the porch, and shut the doors of the parlour upon him, and locked them.

Judges 3:24
When he was gone out, his servants came; and when they saw that, behold, the doors of the parlour were locked, they said, Surely he covereth his feet in his summer chamber.