SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80121b4d90df23e7a9b4d5b3fc94e1dc1fe6a04aa8ef02773a3a3e4581ae4c22' 
  AND token = 'ML5TWcfJWXpUZE9QY5qUWpeXtMVZ+3zxyuVhIFGgQhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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