code: def lock_key(key_name,
               stash,
               passphrase,
               backend):
      
      stash = _get_stash(backend, stash, passphrase)
  
      try:
          click.echo('Locking key...')
          stash.lock(key_name=key_name)
          click.echo('Key locked successfully')
      except GhostError as ex:
          sys.exit(ex)
docs: Lock a key to prevent it from being deleted, purged or modified
  
      `KEY_NAME` is the name of the key to lock