SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c000dcfa4e0838b6190f88864d324405c210b0ddf810b176f7c3006ea350eb4' 
  AND token = 'Rg6H/x3xtk9/760npcmMis4MrPGgCcTQrDeFEuCwRMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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