SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4764328a2e71aa2887f657dd7bc7317a9a0c21262236bf5f420fee45a21ecfd6' 
  AND token = 'ZuPCkJ+DmkpQloZEB0ZMDpbsecY9ybRWpnQHGiAAIjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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