SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ef65e21db239c0b3db308763674a3ca6833f63619a316202710716c7cab756d' 
  AND token = 'rqNm5Cqkdf8kRidXb1Pb2KauGZb5tR9RzbDfvBuo20U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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