SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aacf1422e4dc1af15a9f578728745de56c83633aa3d71705d746f15b525a0a8e' 
  AND token = 'F83h3z4HaXQM6yqeYK/d5EViul+TeJDUS8QN9deLUPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}