SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6d092434314017246910fc2a746605fa8d4baf88c687e651b154f53fd32c37ce' 
  AND token = '47eGjDD3GTtVTUAG/KhkF4+F1kgOkq8QIhN+IfAEHy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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