SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df5d4144b3482cee8b7dfceed2e275282ffc350d8e2457dc90fdbed1e3f75c4b' 
  AND token = 'ztUl97IApg/ZqozRIN0zc5nz8BMjfz5HgXwoaW2DQuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

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