SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8891d72acbd75391f0f6a4d2e66f2a085fc27189b11c7b5b1c9623694830987' 
  AND token = '/pD4ktItivZPAa6JvYeW/qYMGzd9Zpj+MPqwgx3eZ5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}