JSOM/CSOM Threshold issue
Please enable support for CSOM/JSOM/REST query to process request for large list rather than hitting into threshold issue. Even the column is indexed and you query based on the indexed column, threshold error is returned.
Default limit on a REST query is 100 items. You can change the default up to "$top=5000". When there are more results for the query than returned, a link is given in the REST response to get the next "page" of results.
As in all queries to a list, if the list has more items than the threshold allows, you need to use filters against columns which have been indexed in order for the query to match fewer than the item threshold. Then, the query results can be constructed and returned in "pages" as described in the previous paragraph.