SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6814994c47628017539911389482685ac41990079661af2494563ac2db10f68f' 
  AND token = '2cyTytlYRbzULRMpzq9QEGwr+ii+pAK/YSvJHM+PUFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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