SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28b123a06a97197838c94d3c4bf692f42d0a81dcf16c5806dc33e52ef8562fde' 
  AND token = 'qN7nHPO7lBASpPe5bKUEJH+iKOHHFwzLBGdoDdeI+jY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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