COUNT(*) with USE KEYS return wrong results

cbq> select count from `beer-sample`;
{
"requestID": "698d6efa-99f7-4368-857f-c489512ea23b",
"signature":

{ "$1": "number" }

,
"results": [

{ "$1": 7304 }

],
"status": "success",
"metrics":

{ "elapsedTime": "16.443185ms", "executionTime": "16.381563ms", "resultCount": 1, "resultSize": 34 }

}

cbq> select count(1) from `beer-sample` use keys ["z1"];
{
"requestID": "ec774d85-86c6-4a34-914c-e36066d5575f",
"signature":

{ "$1": "number" }

,
"results": [

{ "$1": 1 }

],
"status": "success",
"metrics":

{ "elapsedTime": "1.752055ms", "executionTime": "1.717205ms", "resultCount": 1, "resultSize": 31 }

}

In the query below, count is ignoring the USE KEYS.
cbq> select count from `beer-sample` use keys ["z1"];
{
"requestID": "670ee574-d27d-4438-9c6f-0d8c21c5bb98",
"signature":

{ "$1": "number" }

,
"results": [

{ "$1": 7304 }

],
"status": "success",
"metrics":

{ "elapsedTime": "12.417036ms", "executionTime": "12.383154ms", "resultCount": 1, "resultSize": 34 }

}

cbq>