As advice in comment I write down solution.

var handle = _endpointConnector.ConnectReceiveEndpoint(queueName, (bc, hc) =>
{
    hc.ConfigureConsumeTopology = false;
    hc.Consumer<MessageAConsumer>();
    ((IRabbitMqReceiveEndpointConfigurator)hc).Bind<MessageA>(s => {
        s.RoutingKey = (string)keyItem;
        s.ExchangeType = ExchangeType.Direct;
    });
    hc.ConfigureTransport(cfg =>
    {
        cfg.ConcurrentMessageLimit = 20;
        cfg.PrefetchCount = 20;
    });
});