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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '668e5e75e0d50902024dab07b07ae38a4ba079efd16ad667c4c439986cff15e8' 
  AND token = '/6pTU2jax5+K1qFqhJjcH4LFCJfcSX1IV1DB81thWSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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