SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5472253161933dda9f8fe756e7ab76c0b1541004f9ed8638b268cf443f95532c' 
  AND token = 'PpY6vBKhZ/Fe4m+DDEgUJqQmpajL/YxhARrOs0XB5Xg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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