SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '778e6594750f96682171c6654ff66baeffdb4ebca5061331b5c86db399a9a4a3' 
  AND token = 'nUUKFiMb8LqeIlky1P/oGKAXvanYSHXvqRUmfXJTUjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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