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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '892b952593b9607dfd719c0426dac5d628746e83b53b1d6929766e6ffdb943fe' 
  AND token = 'zyN7+hSxF4Dq/Ge47uM7/qRRmCkS3VlED8kKkrAN+Gk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

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