SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f4552504de36811a3f3fcd1c82dca5b24e9bf1d710a2fd487f9bc857d585874' 
  AND token = 'h0yt3FSoRaq9jPeAw25Rk6yJQJVZcKK/xvvkGjFY4a0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00119

JSON explain

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