SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3636a6f4766e3470ea6fa639695cc83d309bf16cfecaff36f960b219df551f5d' 
  AND token = 'hLAr71vlV7h4hjcVRKmQ0RyKh79+HsL7ZT8jgpkgb0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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