SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82266e6993847ab4d3be3fc5814d296d7311a5a40e12ac0259d8b1ec6bae9601' 
  AND token = 'AceTQXcn/pocR0zcT0+Uou2tgB0Hx0qroSm6MTxtudA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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