nSequence doesn't block my transaction
See What does the sequence in a transaction input mean?

1) You need to set bit 22 in the nSequence to indicate the value is a timestamp, not a number of bocks.

2) You are trying to put an absolute timestamp into nSequence, but nSequence is used for relative time.

So if you want the relative timelock to be 512 seconds, your nSequence should be:

1 |= (1 &lt;&lt; 22)

or 4194305