Yes, it is perfectly fine to marinate chicken for 15-20 minutes before cooking. While longer marinating times can enhance the flavor and tenderness of the meat, even a short marinating time can still impart some flavor and help tenderize the chicken slightly.
Marinating chicken involves soaking it in a mixture of marinade ingredients, such as herbs, spices, acids (like lemon juice or vinegar), oils, and other flavorings. The marinade helps infuse the chicken with flavor and can also help break down the proteins, making the meat more tender.
While marinating for a longer period, such as several hours or overnight, can have more pronounced effects, a brief marinating time of 15-20 minutes can still provide some benefits. Just be sure to coat the chicken evenly with the marinade and let it sit in the refrigerator during that time for food safety.
If you have the time, consider marinating the chicken for a longer period, but if you're short on time, a short marinating time can still enhance the flavor of your chicken.