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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f518a9fe774f29eb96ac50e4d97c0268dffcd817a61c4160374757ca1599ccd' 
  AND token = 'IhVwFDzlzbx5xZNT2AqlCi6q7QstpcNAGNgiT2+4hwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

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