How do I get items from DynamoDBIndexHashKey?

I would like to specify. May I receive elements only from DynamoDBIndexHashKey, not use DynamoDBHashKey?

I have a table with fields

@DynamoDBIndexHashKey (attributeName = "count", globalSecondaryIndexName = "count-index")

I have no @DynamoDBIndexRangeKey

It's code:

 MyEntity myEntity = new MyEntity();
    myEntity.setCount(1);    // Integer
    DynamoDBQueryExpression<NewsDynamoDb> queryExpression = new DynamoDBQueryExpression<NewsDynamoDb>()
    List<MyEntity> myCollection = mapper.query(MyEntity.class, queryExpression);


AmazonServiceException: Status Code: 400, AWS Service: AmazonDynamoDBv2, AWS Request ID: I97S04LDGO6FSF56OCJ8S3K167VV4KQNSO5AEMVJF66Q9ASUAAJG, AWS Error Code: ValidationException, AWS Error Message: One or more parameter values were invalid: Invalid number of argument(s) for the EQ ComparisonOperator

How I can get items from DynamoDBIndexHashKey?

P.s. Scan - work but not interesting to me, because in a further I want a sorting Query with DynamoDBHashKey work. I have problems with DynamoDBIndexHashKey

same example

like explained here

 Table table = dynamoDB.getTable("tableName");
 Index index = table.getIndex("count-index");
 ItemCollection<QueryOutcome> items = null;
 QuerySpec querySpec = new QuerySpec();

querySpec.withKeyConditionExpression("count= :v_count > 0 ")
                .withValueMap(new ValueMap()                  .withString(":v_count","1");
 items = index.query(querySpec);

 while (iterator.hasNext()) {