How is timeout in PostgreSQLConnection different from timeout in query?

Question

PostgreSQL

@override
  Future<PostgreSQLResult> query(
    String fmtString, {
    Map<String, dynamic> substitutionValues,
    bool allowReuse,
    int timeoutInSeconds,
  }) =>
      _query(
        fmtString,
        substitutionValues: substitutionValues,
        allowReuse: allowReuse,
        timeoutInSeconds: timeoutInSeconds,
      );

And there is:

class PostgreSQLConnection extends Object
    with _PostgreSQLExecutionContextMixin
    implements PostgreSQLExecutionContext {
  /// Creates an instance of [PostgreSQLConnection].
  ///
  /// [host] must be a hostname, e.g. "foobar.com" or IP address. Do not include scheme or port.
  /// [port] is the port to connect to the database on. It is typically 5432 for default PostgreSQL settings.
  /// [databaseName] is the name of the database to connect to.
  /// [username] and [password] are optional if the database requires user authentication.
  /// [timeoutInSeconds] refers to the amount of time [PostgreSQLConnection] will wait while establishing a connection before it gives up.
  /// [queryTimeoutInSeconds] refers to the default timeout for [PostgreSQLExecutionContext]'s execute and query methods.
  /// [timeZone] is the timezone the connection is in. Defaults to 'UTC'.
  /// [useSSL] when true, uses a secure socket when connecting to a PostgreSQL database.
  PostgreSQLConnection(
    this.host,
    this.port,
    this.databaseName, {
    this.username,
    this.password,
    this.timeoutInSeconds = 30,
    this.queryTimeoutInSeconds = 30,
    this.timeZone = 'UTC',
    this.useSSL = false,
    this.isUnixSocket = false,
  }) {
    _connectionState = _PostgreSQLConnectionStateClosed();
    _connectionState.connection = this;
  }

What timeout to use?

Now I have this:

List<List<dynamic>> result = await connection.query(body['sql']).timeout(Duration(seconds: 90));

But the code periodically crashes with: "TimeoutException after 0:00:30.000000: Future not completed" as if it were not 90 seconds, but 30. Accordingly, 30 seconds is set in the PostgreSQLConnection.

But I cannot understand how one timeout differs from another.

void main() async {

  connection = PostgreSQLConnection('localhost', 5432, 'db', username: 'postgres', password: '123456');
  await connection.open();

// далее сам код.

Connection like on idea once should be created? How then can it fall?