SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'dbaf9335c4214d7156d64102a30482b2698617cccd8e1faff4f6ade8ce30be49' 
  AND token = 'me/yQJ+yWQ9jg2fAsNJD1ahtykgszcF3pcBQOrRizyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}