SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ded595a25799c1017e8481c9d24775b0bbdddf80fbf3d6cd6bf7939af042cab' 
  AND token = 'U5WZJ+XeXug8cbx4+QkYm8pi9sCa+52PiKR/XVlDvJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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