On a weekend, 45 minutes.
On a weekday, it should take 45-60 minutes, but it can take 90-120 minutes, it cannot be predicted.
Best bet, leave your hotel at 6.30AM, you'll probably be fine.
Take the all-carpool lane route: I-5 to 91 to Harbor to 105. It might not be the most direct route, but you'll always have a carpool lane.