You can use Where to filter results.

Sql

Delete From Table_Name;
Where
    Column1=some_value
and
    Column2=some_another_value;

JsStore

connection.remove({
    from: "Table_Name",
    where: {
        column1: some_value,
        column2: some_another_value
    }
}).then(function(rowsDeleted) {
    //results will contains no of rows deleted.
    console.log(rowsDeleted);
}).catch(function(error) {
    alert(error.message);
});

Example