SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f29e217abf95fa50c96c1bf184180a35dfe14dbc67cd4bed50839b5bb040141' 
  AND token = 'iwFVk1pyQFgfbbi9eGbzwt2KW3RiKmCrSrbGPbNMrig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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