SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d2a9931ebff31670d7bb25bf2ca9c8a1a89541456e4df10e20ee06810365d6a' 
  AND token = 'Lvu+aE9AKOAybtvg8IVIqqLihMhJyxjWdQ7ejL+4xmA=' 
  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"
    }
  }
}