In a large bowl, whisk together the olive oil, lemon juice, minced garlic, oregano, thyme, salt, black pepper, and red pepper flakes until well combined.
Place the chicken breasts in a resealable plastic bag or a shallow dish. Pour the marinade over the chicken, ensuring it is fully coated on all sides. Seal the bag or cover the dish tightly and refrigerate for at least 1 hour, or up to overnight.
About 15 minutes before you're ready to cook, preheat your grill to medium-high heat (about 375°F to 400°F).
Remove the chicken from the marinade, allowing excess marinade to drip off. Discard the marinade. Place the chicken on the grill and cook for 6 to 7 minutes on one side.
Flip the chicken and grill for an additional 6 to 7 minutes, or until the internal temperature reaches 165°F.
Once cooked, remove the chicken from the grill and let it rest for 5 minutes before slicing.