Repair

This lock light icon you are seeing, with the key out of the ignition, does that light blink once every 3-5 seconds? If you insert the key and turn it to the run position just shy of start, does the light go solid then out or does it flash rapid like once a second? If you turn on the headlights, do they shine bright? Now if you hold the key in the start position do the headlights remain bright? When you try to start the engine does it do anything at all, or does it just sit there and not make any sound or movement?

you are most likely experiencing a battery with low amps. That is where the headlight on and try to start test comes in

I haven't checked the headlights but everything seems fine with the car. When I turn it on or even just turn the key a bit forward the security light stops flashing and everything is fine. We drove it around and the engine is still running normally. And I think the headlights are actually fine since we drove in the dark now that I think of it.

When you turn your car on, the throttle body takes a lot of power....so it may be indicating low amperage on your battery. Charge it at home or go to Sears for a quick charge and see if that lite goes out

If you have a Wallmart battery.....I find a lot of problems with them. Try a DuraLast battery or something at the "Gold" level....if you find low amperage. You can go to Auto Zone or Sears and check ur battery out for free.