SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29a3f89ef5f77d1e1febc29c1a6163e57b0609df532365370dd8b0f4b7c1e437' 
  AND token = 'n6n1yTyTbV42Wvp83ww/ORB1QHWYBDR4ytJ1gQInOug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables