SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '435e4adea1438980ca0586476947e5cdec511cbfd21eb7ea958d356109def3c7' 
  AND token = 'kDs53NeZJ4ADG+HzQ4WsIAyvWAsF0162TUpSd+v1XKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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