SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a10700a1817006498fb06b564f93443e047d55e4ce2c99a3c43133bc1d8724bb' 
  AND token = 'aHE2Rb1K+tf27SVsah5fxNrtKWArbNhRL7QDlW9hDkc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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