SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a7061515adbe74801290fca56e09da2939030df9aeb57d43a2a6a14874a4af9' 
  AND token = 'B5dAws3PR0EKFZ5QEm/lCYZOyJRMuKIIeGa8TjyDc8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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