SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03ff6476c67a99555fb169b1fa92b56c701f4bb604f5462a5385dd64c49cf451' 
  AND token = 'YBM2EmwjMgDAgngB4FfJmMz9oXZDNqE7Mm7izqPAn5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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