SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd96da522240372b5731fefd6c3799459d8136f485fb367d04fc2b0c24168ba85' 
  AND token = 'usByRopB9IRpsMSsHdA335mUWCMzJf06Ox1azWUPb+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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