SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4908da10f3cfa868b75aa00d1faa25501770125b07730e0f129d173239e225af' 
  AND token = 'LdQGkzCkGCRK0F+PinHhGEmFVywX5BGOOt+iGCUQTYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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