Try:
var client = new RestClient("http://myurl.com/api/");
var request = new RestRequest("getCatalog?token={token}", Method.GET);
request.AddParameter("token", "saga001", ParameterType.UrlSegment);
// request.AddUrlSegment("token", "saga001");
request.OnBeforeDeserialization = resp => { resp.ContentType = "application/json"; };
var queryResult = client.Execute(request);
Console.WriteLine(queryResult.Content);