POST users/user/_search
{
    "query": {
        "filtered" : {
            "filter" : {
                "term": {
                  "email": "very.simplemail.a@gmail.com"
                }
            }
        }
    }
}


the doc:
{
   "_index": "users",
   "_type": "user",
   "_id": "AU4mjbm3x1kxwO87TEnO",
   "_version": 1,
   "found": true,
   "_source": {
      "email": "very.simplemail.a@gmail.com",
      "password": "aaaabbbCC123@@",
      "is_activated": false
   }
}