SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eec81926b27a01b2aedc7117ccb69b404ad20e35d02e633900314a109e1ebfe5' 
  AND token = '0KVpodTA+nLQAf8DGrLMUtcht1t7sOs+Jy8ZXIvI+Jc=' 
  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