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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71d1ca250b2861549d18448c2c5f0ab661cd24462713fafbfa16935542c46b7c' 
  AND token = 'pZnyNLK6Mo1Np9z443UUtQhT08NhaoflGzMfBvEOqf0=' 
  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