get all indices that have a doc older than 3 days

example.txt

GET /logs-*/_search
{
  "size" : 0,
  "terminate_after" : 1,
  "query" : {
    "range: {
      "timestamp" : {
          "lt" : "now-3d"      
      }
    }
  }
  "aggs": {
    "indices": {
      "terms": {
        "field": "_index"
      }
    }
  }
}