SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c984c2eb8a055c373d1faf19dc5561f5298bd102bd4473df3315270571418ae' 
  AND token = 'wVDf1ZntFGbsR5nEgoDYSr2Zh1EeCcYN7GRWDtvOM4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

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