SqlAlchemy / mysql - selecting date by executing math on date column

I have a sessions table with session_start and session_end, both datetime fields.

+---------------+----------+------+-----+---------+----------------+
| Field         | Type     | Null | Key | Default | Extra          |
+---------------+----------+------+-----+---------+----------------+
| session_start | datetime | YES  |     | NULL    |                |
| session_end   | datetime | YES  |     | NULL    |                |

I have incoming hits, that fit into session if they happened no earlier than "session_timeout" seconds before session_start and no later than "session_timout" after session_end.

I am trying to write sql query that will return matching session or nothing based on hit.remote_stamp (python datetime object), but so far it always returns empty result.

matchingSession = models.SessionList.query.filter(and_(
models.SessionList.session_start - timedelta(0,session_timeout) <= hit.remote_stamp,
models.SessionList.session_end + timedelta(0,session_timeout) >= hit.remote_stamp
                )).first() 

if matchingSession:
 print("Updating existing session.")
else:
 print("Session not found. Creating new session.")

it always going to "else" statement and create new session even if it should match existing session +/- session_timeout value (it's set to 3600 btw)

EDIT (as requested in comments): Here's a sample of hits:

MariaDB [cbts]> select * from hits limit 10;
+-----+---------------------+---------------------+------+---------+------+----------+
| id  | stamp               | remote_stamp        | hits | quality | accu | is_valid |
+-----+---------------------+---------------------+------+---------+------+----------+
| 126 | 2021-12-27 13:41:11 | 2021-12-27 13:41:10 |   16 |      37 |    2 |        0 |
| 127 | 2021-12-27 13:41:17 | 2021-12-27 13:41:17 |   16 |      41 |    2 |        0 |
| 128 | 2021-12-27 13:42:02 | 2021-12-27 13:42:01 |   16 |      41 |    2 |        1 |
| 129 | 2021-12-27 13:43:03 | 2021-12-27 13:43:03 |   17 |      39 |    2 |        1 |
| 130 | 2021-12-27 13:43:15 | 2021-12-27 13:43:15 |   18 |      43 |    2 |        0 |
| 131 | 2021-12-27 13:47:31 | 2021-12-27 13:47:31 |   18 |      50 |    2 |        0 |
| 132 | 2021-12-27 13:49:19 | 2021-12-27 13:49:19 |   23 |      51 |    2 |        0 |
| 133 | 2021-12-27 13:49:44 | 2021-12-27 13:49:44 |   13 |      32 |    2 |        1 |
| 134 | 2021-12-28 15:25:37 | 2021-12-28 15:25:36 |    4 |      40 |    2 |        0 |
| 135 | 2021-12-28 21:58:44 | 2021-12-28 21:58:43 |   34 |      30 |    2 |        0 |
+-----+---------------------+---------------------+------+---------+------+----------+

if remote_stamp fit into existing session, it should do some additional stuff (like increment session hits), otherwise - it should create new session.