linkWithParams.cmp

<aura:component implements="forceCommunity:availableForAllPageTypes">

  <!-- private attributes -->
  <aura:attribute name="url" type="String" default="" access="PRIVATE" />
  <aura:attribute name="token" type="String" default="" access="PRIVATE" />

  <!-- CHANGE THIS TO YOUR COMMUNITY SITE PREFIX -->
  <aura:attribute name="sitePrefix" type="String" default="/ltng2" access="PRIVATE" />

  <!-- component events -->
  <aura:handler name="init" value="{!this}" action="{!c.doInit}" />
  <aura:handler name="eCommerceTokenUpdated" event="c:eCommerceTokenUpdated" action="{!c.doInit}" />

  <KGRenewal:eCommerceCartTokenProvider aura:id="tokenProvider" />
  <a href="{!v.url}">Nav with token: {!v.token}</a>

</aura:component>

linkWithParamsController.js

({
  doInit: function(component) {

    var tokenProviderCmp = component.find('tokenProvider');
    component.set('v.token', tokenProviderCmp.get('v.eCommerceOrderToken'));
    console.log('Link got from provider: ' + component.get('v.token'));

    component.set('v.url', component.get('v.sitePrefix') + '/apex/KGRenewal__TransferSession?nextURL=' + encodeURIComponent(component.get('v.sitePrefix') + '/apex/TestCookieTransfer') + '&kg-ecomm-id=' + encodeURIComponent(component.get('v.token')));
  }
})

TestCookieTransfer.page

<apex:page controller="KGRenewal.ECommerceCartController" showHeader="true" sidebar="true">
	{!eCommerceOrder.Name}
</apex:page>