code: public boolean isIndexed() {
  		boolean indexed = false;
  		Extensions extension = getExtension();
  		if (extension != null) {
  
  			ContentsDao contentsDao = geoPackage.getContentsDao();
  			try {
  				Contents contents = contentsDao.queryForId(tableName);
  				if (contents != null) {
  					Date lastChange = contents.getLastChange();
  
  					TableIndexDao tableIndexDao = geoPackage.getTableIndexDao();
  					TableIndex tableIndex = tableIndexDao.queryForId(tableName);
  
  					if (tableIndex != null) {
  						Date lastIndexed = tableIndex.getLastIndexed();
  						indexed = lastIndexed != null
  								&& lastIndexed.getTime() >= lastChange
  										.getTime();
  					}
  				}
  			} catch (SQLException e) {
  				throw new GeoPackageException(
  						"Failed to check if table is indexed, GeoPackage: "
  								+ geoPackage.getName() + ", Table Name: "
  								+ tableName, e);
  			}
  		}
  		return indexed;
  	}
docs: Determine if the feature table is indexed
  
  @return true if indexed