SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24629a53ce39838ad20e3dd36fd5597814046279724f2a745bd2ad9a244dc540' 
  AND token = 'ueiWElGarrbDO7WQww17IzE5NvgeToXv+U0soffgC78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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