Computer or Medical question (for mechanical geniuses)

Laptop cable locks, no prob. If I wanted to purchase a(Lenovo t420)laptop dock on eBay with only 1 key or no key(s)is there a solution? (Cheaper than just finding one with keys)? Back in the day, I can imagine someone looking for a key to their storage box of 3 1/2 floppy disks. What if someone came in looking for keys to their AED defibrillator cabinet? TIA Jon