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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80f8c077467ad0c5184838e1d37fac42a9cb9b796b5da5093e9660af1addd62b' 
  AND token = 'm4Tz1dHGdhNfTpfDPLWyg4AWUJ4AZYm7Bp4WcDH6fKM=' 
  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