Section 25400 shall not be construed to prohibit any citizen of the United States over 18 years of age who resides or is temporarily within this state, and who is not prohibited by state or federal law from possessing, receiving, owning, or purchasing a firearm, from transporting or carrying any pistol, revolver, or other firearm capable of being concealed upon the person for any purpose specified in Sections 25510 to 25595, inclusive, provided that either of the following applies to the firearm:
(a) The firearm is unloaded, within a motor vehicle, and locked in the vehicle’s trunk or in a locked container in the vehicle.
(b) The firearm is unloaded, carried by the person directly to or from any motor vehicle, and, while carrying the firearm, the firearm is contained within a locked container.