SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bfaa33383af71f3232bf784b334fc6ec4b989654a23a276c3b58650fe333fb2' 
  AND token = 'jnF62kqxRHLFVelcCtwskbwS/k45eZELrv+xmps4CW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}