With 90 minutes to go you should be mainly focused on hydration, carbohydrate intake, caffeine and beet juice. Now is not the time to eat high fat or high protein foods as they take more time to empty out of your stomach and won't serve you during your event. The focus would be on easy to digest carbohydrate-based foods or sports drinks, depending on your preference.
Let's look at each one individually, starting with hydration.