SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b78ceeb81faeb4affd897931bbaa1a43a1629a806c214c229bfdcd5ecea22aba' 
  AND token = 'k5HEIQVX0g9Vq+vcOvvW0QPUkkAhyCDO8Fwq0YrAYeU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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