SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59fb1ac364d955f6af3aee794cf2726310aeba73bd43b73a417a7b4054cc3403' 
  AND token = 'yN+LZHuZv/MPL6oYu9cvpdkr9835Ow4udU9y5sdTK0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}