SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3859c16598dee01d506eeaf055192814e3f88aca8a6fc602dc7850f66386aaad' 
  AND token = 'XuIXakWAqcJYzLiGmCRxyiny1PzPzoy831WcDTZmIEw=' 
  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