SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4df873ca2f8e1e337250dcf8ca5dd1862a6e075f8c46630a5bb0a4efd8313bae' 
  AND token = 'AxCnu7Mh8ika0nJPOCR1KPvhiNUoZLRFbISBUI7yJSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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