SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8f48d4cad0f7571e63c22b671383908a507a7597581c25a04291a63b9194d942' 
  AND token = 'fbMjn3qLl15/Cumu28cIqPQVK2kAi7Lzz7n+YDdiDkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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