SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f636cc5994ae81f0c36f4274942d0f62eb5c30a46ea6add764e86c0003c2e16a' 
  AND token = 'fd4EClGVsky5b0oI5dKoaHvgw0ptBrC0nlp/hT2wQj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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