good question because being able to charge phone without having key in ignition is good idea. charge for hour or two and no problem starting the car, no problem at all. lighter receptacle would be off when key taken out of ignition, true. Late model cars have extra power outlets (12VDC) I guess your car doesn't have the extra power outlets. The extra outlets somewhere in the car, say trunk or compartments, or cabin... those outlets are always on (its my guess) But lighter receptacle is "switched" on your car.
Solution: tap a wire. with key out, test for 12V on one of the bunch of wires under panel under drivers knee or passengers knee. This is tidious work but it is not so technical or difficult. Buy the power receptacle at autoparts store (some have three receptacles) and hardwire this to extension wire. you want to extend the wire so that you can place/mount this new receptacle at a particular location on dash or glove compartment.
say you found the positive 12V. tap, splice do what you can to have new wire connected to this one. Guide this wire you just put in and route it away from view and hide it under something and so forth. Take this wire and route it to where you want new receptacle to be. Look carefully on this new receptacle location. Somewhere close to it, find ground/chasis metal of car body. Drill tap-screw into metal and connect wire. This wire is for the negative that connects to " - " neg of your new receptacle.
this job could take you two or three hours if you are a beginner at this kind of stuff. Or you could have a friend do it for you who can do it in one hour.
But this is the only way that you can get new receptacle on your car. I must say it is a very practicle accesory. I got the triple receptacle kind, so useful and always on for my gadgets. that is your basic how-to. good luck
RAV4 has V6 model? I didn't know. what a fine car. It would be like driving a Maxima... horsepower.