SoCal

I'd also bank on 90 mins. You need to get off the plane, wait for your bags, wait for the shuttle to your rental car facility, then get in line, rent the car, get the car, check it for dents, etc. Let's say 11:30-12 you're on the road. By what time do you want to eat?

You don't give any idea of type of food or type of restaurant you're looking for, so I assume you just want someplace to eat (I know the feeling, as myw ife can get hypoglycemic if she doesn't eat after a certain time). I don't see going all the way to Pasadena to get to RC, but there are worse routes. Where in RC are you going? I'm not an In-N-Out Fan and my wife doesn't like burgers, but the chain has its devotees on this site. There is, as noted, one near LAX. There are several others along your route, though I don't know how easy they'd be to see from the highway. Plenty of restaurants, including fast food (e.g., Carl's Jr.), coffee shops (e.g., Denny's) and more upscale (e.g., Proud Bird) near the airport if you want to get that done before you hit the freeways.

I-105 to I-605 sounds right. Whether you take the I-10 or 210 could depend on exactly where you're going. I personally prefer the 210, but if you're going to a hotel on the south end, let's say, near Ontario Mills, the 10, or even Hwy 60, could work. Check Google Maps or Mapquest. You can hit bad traffic at almost any time, especially if there's construction, but your schedule should get you to RC before the worst of rush "hour" starts.

BTW, by out of the L.A. area, do you mean beyond downtown? Out of L.A. County? It's pretty much just one urban mass from LAX to RC. Pretty hard to know when you've passed from one city to another unless you see the green signs along the freeway.