SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16fc314ced3575799390de7a0b659a9e94f8d792e382da75dbbc3a91fc103ec7' 
  AND token = 'yl9zMM7yM/25OOVWpdUmkn5syU8KayjPT5WLY8a92Lk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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