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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64bcb39f70bda0dcc90373616d6f137fe6cc0b94d76ed23747a79b09cf4cd464' 
  AND token = 'YrZkMt2GcdEkYLWX6pAIvBMfCFmAUMoYXpoQaTBLj3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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