SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4342bc30e41e1c237ea26f5c82bd51962f9d7cd753643d9402c82a9c3fc851d' 
  AND token = 'Q42qyDpDSnSAFgjZnZIfDUpjnPnyyv/Jm2CjNAt/bIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

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