SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9324074318acb44c2417f171dd310323abfd4b4f865f4cf81130f490439b7951' 
  AND token = '0Kkb+F8CACEzDlliJjvyLZ9X/U/pYjCD+RpuO6Uv9b8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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