SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79527ad09b390ba9f3736be7159dd58ce40bc7a1723c405a8e5e3b34714baddf' 
  AND token = 'IBFll2hFxotoj+CV9AaSrBNqJu31Q+TTM3jzdDID9Uk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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