SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '302f8fb90af8b51f826d567749bbf768dcf650b0d5657d6b40f18a2587e773c7' 
  AND token = 'dBU271YoLKjeiKge2zV1BFPzqlaUdgqbufVRy/FTEqY=' 
  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