SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70fbfdda1a84493144a77283bc08cd663fa979522939dfb8d9b11513311bd79e' 
  AND token = 'TD3uq2IVGYSqUTvyrkTy6gaOdf+41HHggwjgDrPQQ/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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