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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e75a5aa18b83cfe32340744ba5f7c47d40e01c1d49779266c6dd704874781387' 
  AND token = '3erLXSnTQODNpGFnzrzZsPkagaG2r1PLPD1fgHsyfmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

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