SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '661e25a04f497a6b3f72f6d13e34b62ae85410d2102608de237b4b804def01cd' 
  AND token = 'n0TAhn6W+aSzJbGktaLgah60jHcKg+eEBZxtn5NJJBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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