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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f57c3d86d7ce08bf8557d3651fed00e91eeeaaee6dd0947d35cc77dd82978bc' 
  AND token = 'Bz/HTC9HQch3jb6DDPHoFl9zAHNOGGDA2J+5w4TkpwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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