SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b826040f206cef3b5247dfae4dd97cbf04301322ce13c6174e831a164c54b50b' 
  AND token = 'L6znOuWnUGxeebw3Fsg7hmBJVnHGzoqVAdp42DzLK6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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