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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4971ed5c849bb12c3bcecb10623cd616fff6694a6f05744ecc4c925c4f0588a' 
  AND token = 'JyyaSJeNSyxmTRMFZAytk8ENV5zpmCtP6SnzPD9meAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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