SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ec96628a2f4911517e61906476f2b3cf9f0bbad1b138ce86f308bb130aa75dc' 
  AND token = 'vVs8/ZoLJHkQ9Gwgg4vEtVZ6O3x3gkuzyiSTDtiE2TU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

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