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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c14b26fab374e56585ac9c1fff7a88e001714f5324256bb50d4c34f32e97f762' 
  AND token = 'uyBA4EnS7xp7Fj1dkovEGCwLpOwCSdRZ5N6DItPSxuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

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