SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbccbdbc6a4c94370a69e272cf87c919b5946de34922f99b39879d4d2102f2fc' 
  AND token = 'BbhgnAV8PXROpJcVt+qWRslMCkQ3CeQpXw/jLxo2iJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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