SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84dcf60f74685aa66bfbf43971ab33d4b31fa2bf1e271065c46daea681a263ce' 
  AND token = '6Wa+oMwcdFI7FnsVl57WWJK4TyoP8VIB3Mi4mooIYcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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