SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6218fd64d6341d4301d0c495c0070c68dc4d9c9cef55ff33ffb1848f0ecdc4ff' 
  AND token = 'At7rJK3bdTEyyBCc/Yc71dNiXVjgqaid2tVOn3G5azc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

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