Sharepoint Online - Filter and Paging with more than 5000 items

Hi experts,

I have the following problem: 

I need to get more than 5000 items from a list with many items in order to do some Charts. I created a script and populated the list so i could do some Load Testing.

My REST query is failing because of 5000 item threshold, but i am using paging ($top=2500) and i am filtering over an indexed column. 

My query is like this:

https://mydomain.sharepoint.com/sites/mysite/_api/web/lists/GetByTitle('MyList')/items?select=ID,Column1&$filter=Column1 eq 'Something'&$top=2500

Why I cannot return filtered items with paging if i have indexed Column1? Is there an alternative to this? 

I guess i could start filter by ID gt something and ID lt somthing, but I believe is not an elegant solution.

Regards

Andres Nebel