SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13d55c96d4fa3c4136066c58b912b164d8ec0fe59b1b30296ada3766a9ea88f7' 
  AND token = 'KQUc0QVw4OdZDe4ruOjh9lDb7LFegs9jX4/z9hWLKkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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