SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a640858680f4bb9fe8583f075ff0453dff7bae83b4e9789903c50a37bd957c86' 
  AND token = 'jMQZWQ+Xny91tDnowPlDVIgrbD2rTFMCejY6+SwBY4k=' 
  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