SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e191fb3028507fd8b4080ce855dc88442b0bba99e30d3cbdec4fa91074c59c1d' 
  AND token = '5G3EliYYTiKaVv3D6enRWganxW0IiRPFbZA507AK4sU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}