SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '429f752c34548ae7a00f13ee9788990044b46854cebe6926ec10b4f87eecdd3d' 
  AND token = 'dDpy5fzGS8T2j1pWS3zEpQfXOSd2hthquujUP3Y6WLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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