SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '872ee3d707c7410427517e34eec79dd8db7cda69c180fee0995330e3ecd756ef' 
  AND token = 'MiG9hqWSC/N8Tk3I+ynca1A1vc/+yPrydFW/ksvfT8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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