SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48ba862432cb0be676559e8a436df79509652ff6095b30052be6a11d6d5296fa' 
  AND token = 'WXn/KKAL+CnCXTH7eq4l6GHN5aLUQoL/jWBRPwJF56k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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