Where is the red key?

Hint 1 of 6:

It's on level 1, way at the end.

Hint 2 of 6:

You must run through this secured place and you will lose health.

Hint 3 of 6:

Go fast and watch when the forcefields deactivate.

Hint 4 of 6:

You don't NEED the key, by the way..

Hint 5 of 6:

When you find the door that requires the red key to open it, walk around to
the back or the "secured room."

Hint 6 of 6:

You will find a crack.