During hours of operation, all firearms in a family day home licensed pursuant to § 22.1-289.011 or voluntarily registered pursuant to § 22.1-289.011 or in a family day home approved by a family day system shall be stored unloaded in a locked container, compartment, or cabinet, and all ammunition shall be stored in a separate locked container, compartment, or cabinet. The key or combination to such locked containers, compartments, or cabinets shall be inaccessible to all children in the home.