SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c90a14927558d86c85e38fb4a3b76497ea91f7d4b0402c57037dd0b2e915a77' 
  AND token = 'xpt/GzQqVZfK6yueibKIrZ/kSptFQpels3gstituoPo=' 
  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