SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '830b85e6e8a0a079b324d8a0bc4a8166a13f554e5142ba571bb58a961702c6a9' 
  AND token = 'F866AkOo+FNa4hvtQOlRYUyHuEM/jUY9QBKPyXOjs3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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