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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50084779c12f263722bb556f34375c14a14c38a9ff5d86708e8461a5ce121a85' 
  AND token = 'vrSkk469j5I3rrqIlT6Itq4txhJo2mAWxtwoinQru1U=' 
  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