SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb718d252aaba557f70201acdb6a8acc15198d110bc21dfe31517d93a25026e8' 
  AND token = 'aD1LKlL82+7pq5KlcRaPWQLBk5rOipgJLECpZi6Meww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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