SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1dff093412dd5a23f53bf64abcc142d47329f4103738f404f01c81ad695d25d6' 
  AND token = 'ASiRphrN9D9LNCwGjkvxxrz2JAO5eRPuAMUIqOZRKrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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