SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb48f109ea2398835ffa7c7913b9448afc7aacd5f0651c788dbbc570d4e39854' 
  AND token = 'VKxgbYxS80oZsfoVIICHoC6LFbFX3LD4ISze9dyDjW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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