SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb34f18eae77447c66d1b2ac53b562d4be338297da6c736eec9939f6afc3852f' 
  AND token = 'dSZCKxGQHTRT+CYZa3VHOjb2cPh3J4RUi/EjZdKXqG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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