SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54075574fd2af4838464d8a10913871ca280cc61b57153568504b40c42770953' 
  AND token = 'cYlD1AcU2ktgPZMh16h50O14nB/OpmBNU7++YRcDkvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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