SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63cb1871a2a89a316916b6ca189c734bd3c60336212193fc98777768a9f1e75e' 
  AND token = 'TYUCOwS/MHKC/lQsukpVUFQUCV49nhEyrGD+LiPeI9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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