SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa729f4faa72b1f73b232b84fdf05758e0f42a76a7912bffc4f306555c150086' 
  AND token = 'xgW7Itd6dTAAMc8vPzoCtHPS9u5sVVuvIaatbn9TbgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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