SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd824373ee1b442595ea9b0160eb6e51e9a8bb40962988d3470561d769a7835cd' 
  AND token = 'Rs0M/Fwxg4jivBhPm9IESzj3AZ1tUhHoMz0rKfJCjf4=' 
  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