SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 4)
   ExpressionList (children 2)
    Identifier timestamp
    Identifier value
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier mytable
   Function equals (children 1)
    ExpressionList (children 2)
     Identifier key
     Literal UInt64_5
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier timestamp
