SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '427087c6e8c5f48360d5bc46f6bf2524b7b6455f9ca644c40b6e79e0b0aa436c' 
  AND token = 'yFugvYs5RHOVbNx5Azlv1zaYAlLsbD6pbJYoyzVU9pI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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