SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b74d0f6384b1da919506cf117e494dd5cb21e1651a6d4304a8c64ab6f6ed428f' 
  AND token = 'Xh2N/WR4FdaF+eAMWmUs77+cRlAqRJAUOnxfbRUjOGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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