SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '30f343ea7c0d59551357cf3873d2437166429f8d7f0e7145eb5d797ea6d14f2f' 
  AND token = 'sVf9c+ms8C/YENkhsGIqO9yoRpl5Oc3wXVxvuSWCqQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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