SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d5cd84bcd306b4730698f8228bbe98963505f9139acb292f2e17262fb93e385' 
  AND token = '277tgf/tgJKXk77PmTHJhssTBdyAQ9Xa42pXQ0DKYic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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