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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bac5bd879383a09a11de9830ed477406d1ac4a3f6d52a2c2622fb7dcb193258' 
  AND token = 'jSsrVkeCdEw1SPpP1DvSxs6bdfkvFGP9sFocIIO69oo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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