SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9675a24e850b6dd65134367a4518bce5ece1597069fd67143009bc9a81a1e10b' 
  AND token = 'kld9BmK0ZqG9m93tcC78e6E8d7VwSW9/GjLozQ3VSBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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