SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b535bf8167ca90693f01dc4d36cb88ae4785e89363726e10a03a54249c016fe' 
  AND token = 'Ll2RcoH+PN3cDNoegdOdwyvvUILEiIhoUcC9q3xaRGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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