SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97c791bb07230c389ca12a806d555c8fc96971f8d522ede6b2fe94b608980e08' 
  AND token = 'ncx7EQet6tzZoPAFc/8e8k4IuxS5sBtmqnjEaOZQwFE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

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