SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17d503969cb534af5caa536f1b64da7a06f3715b7f8ce2fc2e6efaa52c4e4f7c' 
  AND token = 'M7IpdUQUq9zxBbbiXzr7gg2dKvmNH+aLtsaNU1fGeT8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

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