SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1025d1776f3810cb462ac64493e5cb22388363bae56789c69814372ebd1eb14e' 
  AND token = 'rt29iaINIIZE3samoNreCLXQ400rmFZ/YbI7XLCXjmI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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