SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '637a8a4eac6f1a045b8a030dfd18787835dbbb0cd1f15aaa1489183a12bf5a42' 
  AND token = 'JYMapb2O1GiRQg7WCHWGM+OUVEmto7ZwjYRueTuAFss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

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