SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '841697bf6dcee9c60e638214c864da6b2136444a8a93cd503864f80d6623a314' 
  AND token = 'dIWdswhZG/k/W3Mx9kyH8vWEP7CDi4SFmRZBHGJyYlA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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