What is a key lock? Is it asking for a PIN on your lock screen?
No, that doesn't happen by itself, especially on WP8.1, which is a pretty solid OS (compared to W10). EAS can push a requirement for a PIN, but even then, you have to set it first. Not setting a PIN will not allow email configuration. Ask your IT guy if he set one up.
Try these in the following order
1. Go to your
microsoft account on your browser, locate your phone, go to find my phone, click lock, select a passcode and lock the phone. This will change the passcode configured on your phone.
2. If the above doesn't work, you have only one option left-to factory reset the phone. You can either do it from the same page as above using the erase option, or use the method below
3. Switch off the phone. Turn on the phone keeping the volume down button pressed. it should come up with an exclamation mark. Then press the following four buttons in this order:
Volume up,
Volume down,
Power,
Volume down
