core/src/main/java/com/orientechnologies/orient/core/sql/parser/OBaseExpression.java
public boolean canExecuteIndexedFunctionWithoutIndex(OFromClause target, OCommandContext context, OBinaryCompareOperator operator,
      Object right) {
    if (this.identifier == null) {
      return false;
    }
    return identifier.canExecuteIndexedFunctionWithoutIndex(target, context, operator, right);
  }
public boolean canExecuteIndexedFunctionWithoutIndex(OFromClause target, OCommandContext context, OBinaryCompareOperator operator,
      Object right) {
    if (this.identifier == null) {
      return false;
    }
    return identifier.canExecuteIndexedFunctionWithoutIndex(target, context, operator, right);
  }
tests if current expression is an indexed funciton AND that function can also be executed without using the index

@param target   the query target
@param context  the execution context
@param operator
@param right

@return true if current expression is an indexed funciton AND that function can also be executed without using the index, false
otherwise