SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '34baabf5c52870be9cfb08eee6cf9b20e351a1e78e4acd24b8a4bdec063f7a94' 
  AND token = 'RcD2BipZkjIZ2C2PDGSxxGhzz16J8ZRJbOAxTu5zumU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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