SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0007cbb7d9385e91436dd0a43219015fc18a7af05c894771a066ca0e2792519d' 
  AND token = 'EI8SY3Cgd4aZ6bdShwQbkn7PcBQ3SxMYc+Stl17iaD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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