To lose keys indicates disappointments, obstacles, and setbacks, while finding keys represents discovering the perfect solution to a problem.

To give someone you know a key implies that you will offer assistance to that person, while giving a key to an unknown person indicates an improvement in your own circumstances.

To be given a key augurs assistance from friends in positions of power.

To fit a key in a lock implies romantic and sexual happiness; unlocking a door indicates a breaking down of obstacles.