SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad82e256e3e03e26a9ffb3ce28c5b5aca50f615e00a3f4ae2ae39aa4cdd0f4dc' 
  AND token = 'x+Z22R3QsqJZdBjkAmOzJuRsXAtCKDU0GVKriYBGeBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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