SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3726aa45d02aee7cbfc01e68e4dff47f5dae059fa307c0dab56ba7e5ef337a75' 
  AND token = 'Vb4o4evkxDsWoZcxEZD56ZZuUGu2y2j3XF047prJ0qU=' 
  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"
    }
  }
}