SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61a634cb85432343297833495342abf6eaf2a00280aa33a9320a8e58279ddadd' 
  AND token = 'Y6OHlOIYzKKVeDfwszmuxKcBEhnjZLLEuH7/x129SpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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