SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '245fe0f13fe3eede82655b6eef16a9343df474574bef83d7a15443205c440caa' 
  AND token = 'GDtkUowbtJ/QTvxTIv67NtWPL7O3PrBRZ4JiB2E8m5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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