How to ignore a field from search if the field is not part of mappings?

The document in elastic has field mappings only for the fields catalog and @type . now if a user sends an non-existing field ( countryCode ) in the search, is there a way in elastic to instruct to ignore the field in the search (even though its available in the request) ?

{
    "query": {
        "bool": {
            "must": [
                {
                    "query_string": {                       
                        "query": "(\\*catalog\\*:Trunk) AND (\\*@type\\*:Product) AND (\\*countryCode\\*:USA)"
                    }
                }
            ]
        }
    }
}