Always reproduced:

```
milovidov-desktop :) create table table_map (a Map(String, String), b String) engine = MergeTree() order by a;

CREATE TABLE table_map
(
    `a` Map(String, String),
    `b` String
)
ENGINE = MergeTree
ORDER BY a

Query id: 8f8120c1-c165-452a-815f-2bcae3957e2a

Ok.

0 rows in set. Elapsed: 0.002 sec. 

milovidov-desktop :) SELECT b FROM table_map WHERE a = map('name', NULL, '', NULL)

SELECT b
FROM table_map
WHERE a = {'name', NULL, '', NULL}
```
if (isDateTime64<Name, ToDataType>(arguments))
            {
                timezone_arg_position += 1;
                scale = static_cast<UInt32>(arguments[1].column->get64(0));
                if (to_datetime64 || scale != 0) 
                    return std::make_shared<DataTypeDateTime64>(scale,
                        extractTimeZoneNameFromFunctionArguments(arguments, timezone_arg_position, 0));
                return std::make_shared<DataTypeDateTime>(extractTimeZoneNameFromFunctionArguments(arguments, timezone_arg_position, 0));
            }
            if constexpr (std::is_same_v<ToDataType, DataTypeDateTime>)
                return std::make_shared<DataTypeDateTime>(extractTimeZoneNameFromFunctionArguments(arguments, timezone_arg_position, 0));
            else if constexpr (std::is_same_v<ToDataType, DataTypeDateTime64>)
                throw Exception("Unexpected branch in code of conversion function: it is a bug.", ErrorCodes::LOGICAL_ERROR);
            else
                return std::make_shared<ToDataType>();
        }
    }
    
    
    
    bool useDefaultImplementationForNulls() const override { return checked_return_type; }
    bool useDefaultImplementationForConstants() const override { return true; }
    ColumnNumbers getArgumentsThatAreAlwaysConstant() const override
    {
        if constexpr (std::is_same_v<ToDataType, DataTypeDateTime64>)
            return {2};
        return {1};
    }
    bool canBeExecutedOnDefaultArguments() const override { return false; }
    ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, size_t input_rows_count) const override