**Describe the bug**
Under certain conditions the equals comparison between String and Date yields the wrong result. Range Comparisons with greather-than-equals returns the correct result set.

**How to reproduce**
* Which ClickHouse server version to use: 21.2.5.5 (latest at the time of this issue)
* Which interface to use, if matters: HTTP (but should not matter)

```sql
CREATE TABLE default.myTable (
	myDay Date,
	myOrder Int32,
	someData String
) 
ENGINE = ReplacingMergeTree
PARTITION BY floor(toYYYYMMDD(myDay), -1)
ORDER BY (myOrder)
;

INSERT INTO default.myTable (myDay, myOrder) VALUES ('2021-01-01', 1);
INSERT INTO default.myTable (myDay, myOrder) VALUES ('2021-01-02', 2); // This row should be returned
INSERT INTO default.myTable (myDay, myOrder) VALUES ('2021-01-03', 3);

SELECT * FROM default.myTable mt
WHERE myDay = '2021-01-02';
```

**Expected behavior**
The last query in the example should yield the marked row. Instead it returns a empty result set.

There must be a connection to the used `PARTITION KEY`. The issue fails to reproduce as soon as I do any changes to the `PARTITION KEY` setting.

for (const auto & key : key_columns)
        key_names[key.second] = key.first;
    WriteBufferFromOwnString buf;
    std::function<void(const Node *)> describe;
    describe = [&describe, &key_names, &is_key_used, &buf](const Node * node)
    {
        switch (node->type)
        {
            case Node::Type::Leaf:
            {
                is_key_used[node->element->key_column] = true;
                
                
                
                
                if (node->negate)
                    buf << "not(";
                buf << node->element->toString(key_names[node->element->key_column], true);
                if (node->negate)
                    buf << ")";
                break;
            }
            case Node::Type::True:
                buf << "true";
                break;
            case Node::Type::False:
                buf << "false";
                break;
            case Node::Type::And:
                buf << "and(";