Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71cf2fbdb7ad4935b5f983e1c2d4637d643cc49a75618f2434f1a7992269ed39' 
  AND token = 'qr4x4j4op+TazZfRBllDL48fZc5VRBMp0wN+XOUzL38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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