SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdb599a20132c9fbee918a50986b18b2caf20848a3e9f3bad337a6570c2a4957' 
  AND token = '8wAOWXeC8jYr7Izz2eOV3w3nZKew8sKjGjfds2OuIks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}