SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '81bdd47fcc159021cba0376643709ee7273ed4e173a87ff7a700c225b5ae8a90' 
  AND token = 'iYbS0Gu8L2WZYga6Wa+Mh0aI4Vk3ALPRV0YdQsi5gbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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