SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c1eb3a9c862e1e990ee7054b741227cd08aaa1c06ead3d337ec22886aa236a4' 
  AND token = 'Fkq6Qrcq4ZauiK5h1qqftQ4LD/Uu+iYni1O5s+yI6+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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