SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b7e49c427a810752ee0496aab8797015e3a523780ace0497c713b4940dca670' 
  AND token = 'Mw59namQzWjm9SzZXGkFe/Wk2arIq71PPhtcP1LQ6IY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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