Flash particle-lock-monitor.ino on your firmware updated Particle Core or Particle Photon.
Wire D0 to a switch (or multiple serial connected switches) monitoring lock(s) status. Wire the other end to the ground.
Three printable stl files match the author's dool locks. They make aligning standard microswitches to the locks much easier while having a nice look. Customize them to your needs. Printing showed good results with 0.3mm layer height 20% honeycomb infill.