SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd83b7675e0482a3ca8c48a404e65819b44f6f928292efc6dd09bdef53e1d1995' 
  AND token = 'wOaX+NFJ8rJI0cA74tjb/hJkzBTMdDYLXGGkTcl6yZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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